This invention relates to apparatus and a method for uniformly discharging powdered material in a generally vertical plane throughout an arc of about 180.degree.. Although not so limited, the apparatus has particular utility in distributing powdered rock, such as limestone, over the ceilings, ribs (walls) and floors of underground coal mines.
The practice of "rock dusting" underground coal mines is for the purpose of coating coal dust and depositing the coated particles on mine floors, thereby decreasing the potential for explosion created by coal dust entrained in mine atmospheres and decreasing the likelihood of inhalation of coal dust by mine workers.
Devices for rock dusting of mines are in use at the present time, which utilize a single-bladed rotating impeller which discharges powdered rock upwardly and laterally. To the best of applicant's knowledge such devices are incapable of distributing rock dust in a uniform pattern and require servicing by several workers during operation. There is therefore a need for a reliable rock dust distributor which can discharge powdered material uniformly over the ceilings, ribs and floors of underground mines and which requires only one operator.